TOPIC 8: Vents and Venting System

Question 1

Portion of the drainage pipe installation intended to
maintain a balanced atmospheric pressure inside the
system

Answer 1

VENTILATION

Question 2

pipe or opening used for ensuring the
circulation of air in a plumbing system and for relieving the
negative pressure exerted on trap seals

Answer 2

Vent Pipe

Question 3

• the ‘backbone’ of the entire sanitary
  system
• Connected to the Main Soil & Waste
  Stack
• The portion where waste does not
  travel through

Answer 3

Main Soil & Waste Vent

Question 4

• Continues to the roof; the portion
  penetrating the roof is called the

Answer 4

Vent Stack Through Roof (VSTR)

Question 5

• the principal artery of the venting
  system to which vent branches are
  connected.
• serves as support to the Main Soil &
  Waste Vent
• a.k.a. ‘Collecting Vent Line’

Answer 5

Main Vent

Question 6

a pipe installed to vent a fixture trap, that connects with the vent system above the fixture served or terminates in the open air.

Answer 6

Individual Vent or Back Vent

Question 7

an arrangement of venting so
installed that one vent pipe
serve two (2) traps.

Answer 7

Unit, Common, or Dual Vent

Question 8

a vertical vent line that provides
additional circulation of air between
the drainage and vent systems or to
act as an auxiliary vent on a specially
designed system such as a
“yoke vent” connection between the
soil and vent stacks.

Answer 8

Relief Vent

Question 9

a pipe connecting upward from a soil
or waste stack below the floor and
below horizontal connection to an
adjacent vent stack at a point above
the floor and higher than the highest
spill level of fixtures for preventing
pressure changes in the stacks.

Answer 9

Yoke or By-pass Vent

Question 10

• a group vent pipe which starts in front of the extreme (highest) fixture connection on a horizontal branch and connects to the vent stack.
• a.k.a. ‘Loop Vent’
• Serves a battery of fixtures

Answer 10

Circuit Vent

Question 11

• a vertical vent connection on a
  horizontal soil or waste pipe
  branch at a point downstream
  of the last fixture connection
  and turning to a horizontal line
  above the highest overflow
  level of the highest fixture
  connected there
• Used in spaces without partitions

Answer 11

Looped Vent

Question 12

that portion of a vent pipe through which wastewater also
flows through.

Answer 12

Wet Vent

Question 13

a pipe or shaft to convey foul air
from a plumbing fixture or a room
to the outer air.

Answer 13

Local Vent

Question 14

a vent that does not carry liquid or
water-borne wastes.

Answer 14

Dry Vent

Question 15

the extension of a soil or waste stack
above the highest horizontal drain
connected to the stack.

Answer 15

Stack Vent

Question 16

the vertical vent pipe installed
primarily for providing circulation of
air to and from any part of the soil, waste of the drainage system.

Answer 16

Vent Stack

Question 17

The uppermost end above the roof has traditionally been referred to as

Answer 17

Vent Stack Through Roof (VSTR).

Question 18

Vents Required: Each trap shall be protected against ___ and ____through venting.

Answer 18

siphonage and backpressure

Question 19

Vents not Required: on a _____ which discharges through a horizontal indirect waste pipe into a secondary interceptor. The secondary interceptor shall be properly trapped and vented.

Answer 19

primary settling tank interceptor

Question 20

Vents not Required: ____. Such sink shall
discharge by means of an approved indirect waste pipe into a floor sink or other approved type receptor.

Answer 20

Traps serving sinks in an island bar counter

Question 21

SIZE OF VENTS:
The sizes of vent piping shall be determined from its ___ and ____ connected thereto.

Answer 21

length and the total number of fixture units

Question 22

SIZE OF VENTS: The diameter of an individual vent shall not be less than _____ nor less in size than ____ of the drain to which it is connected.

Answer 22

32 mm (1-1/4”); one-half (1/2) the diameter

Question 23

GRADES & CONNECTIONS
All horizontal or branch vents shall be free from _____ & shall be graded and connected to drip back by
gravity to the drainage pipe it serves.

Answer 23

drops or sags

Question 24

GRADES & CONNECTIONS
Each vent shall rise vertically ____ above the highest level rim of the fixtures served before offsetting horizontally.

Answer 24

152 mm

Question 25

GRADES & CONNECTIONS All vent pipes shall extend ____ above the roof or shall be reconnected to the soil or waste stack vent at a point below the roof.

Answer 25

undiminished in size

Question 26

GRADES & CONNECTIONS ____ fixtures having same level inlet openings, may be served by a common vertical vent pipe connected to an approved double branch fitting.

Answer 26

Two (2)

Question 27

GRADES & CONNECTIONS The “vent stack through roof” (VSTR) shall be increased ____ pipe size above the connection between the stack vent and the horizontal vent.

Answer 27

one (1)

Question 28

VENT TERMINATION VSTR shall terminate vertically not less than ____ above the roof nor less than ____ from any vertical surface nearby.

Answer 28

150 mm; 300 mm

Question 29

VENT TERMINATION Each vent opening shall terminate: Not less than ___ from any openable window; Not less than ___ above any openable window; Not less than___ away from any lot line, alley and street boundary lines.

Answer 29

3.00 m; 0.90 m; 0.90 m

Question 30

VENT TERMINATION Vertical vent pipes shall extend ___ distant from any part of the roof that is used for human activities and shall extend not less than ___ above such roof.

Answer 30

3.00 m; 2.10 m

Question 31

VENT STACK & RELIEF VENTS Each soil or waste stack extending ____ above the building drain shall be served by a parallel vent stack which shall extend undiminished in size from its upper terminal at the roof and connect to the soil or waste stack at ground level and at every fifth floor levels with a ____ at a point below the horizontal soil or waste branch connection to the stack and at the nearby vent stack above the same floor to provide a relief vent.

Answer 31

ten (10) or more storeys; “yoke vent”

Question 32

VENT STACK & RELIEF VENTS The yoke vent connection at the vent stack shall be placed ____ the floor level and, by means of a wye branch at the soil stack, shall be placed below the fixture branch serving that floor.

Answer 32

1.0 m above

Question 33

VENT STACK & RELIEF VENTS The size of yoke vent shall be ____ than either the soil stack or the vent stack, whichever is smaller.

Answer 33

not less in diameter

Question 34

SANITARY SYSTEM PROBLEMS

Answer 34

Trap Seal Loss Retardation of flow Deterioration of the materials

Question 35

Direct effect of the Minus & Plus Pressure inside the system due to inadequate ventilation of traps

Answer 35

Trap Seal Loss

Question 36

Trap Seal Loss: Attributed to the following conditions

Answer 36

Siphonage Back Pressure Capillary Action Evaporation Wind Effects

Question 37

Trap Seal Loss: Attributed to the following conditions: direct and momentum

Answer 37

Siphonage-

Question 38

Trap Seal Loss: Attributed to the following conditions: caused by extreme temperatures, idleness

Answer 38

Evaporation-

Question 39

Trap Seal Loss: Attributed to the following conditions: strong winds blow the trap seal

Answer 39

Wind Effects

Question 40

Due to the effect of atmospheric pressure and/or gravity

Answer 40

Retardation of flow

Question 41

Due to the formation of acids

Answer 41

Deterioration of the Materials

Question 42

is a pipe that does not connect directly with the drainage system but conveys liquid wastes by discharging into a plumbing fixture, interceptor or receptacle directly connected to the drainage system.

Answer 42

Indirect Waste Pipe

Question 43

The process of supplying or removing air by natural or artificial means to or from any space, such air may or may have not been conditioned.

Answer 43

VENTILATION

Question 44

A pipe installed to provide a flow of air to and from a drainage system or to provide circulation of air within such system to protect the trap seal from siphonage and backpressure.

Answer 44

VENT

Question 45

A vertical vent pipe installed primarily for the purpose of providing circulation of air to or from any part of the building drainage system.

Answer 45

VENT STACK, MAIN VENT

Question 46

The extension to the open air of a soil or waste stack above the highest horizontal branch drain or fixture branch connected to the stack.

Answer 46

STACK VENT, SOIL AND WASTE VENT

Question 47

Type of venting system where the vent connects with a single fixture trap, usually at the back and extends vertically and connects with a stack vent, a vent stack or branch vent.

Answer 47

INDIVIDUAL VENT/BACK VENT

Question 48

A branch vent which serves two or more traps and extends from in front of the last fixture connection of a horizontal branch to the vent stack. Circuit venting can be used when two or more fixtures, such as lavatories, are installed in a row. The circuit vent is connected to the waste drain line between the last two fixtures in the row. Then the circuit vent is connected to the main vent.

Answer 48

CIRCUIT VENT

Question 49

A VENT ARRANGEMENT FOR A GROUP OF PLUMBING FIXTURES, CONSIST OF A VENT PIPE WHICH IS CONNECTED TO THE WASTE OR SOIL BRANCH IMMEDIATELY BEFORE THE FIRST FIXTURE OF THE GROUP.

Answer 49

LOOP VENT

Question 50

A type of ventilation system used on fixtures in a room away from a wall or partition.

Answer 50

LOOPED VENT